Preheat the oven to 180ºC.Tear the croissants into small chunks and place them in a large bowl.In a large frying pan, fry the bacon until crispy and then set aside to drain on kitchen paper.Add the butter to the bacon fat in the pan and sauté the onion and leeks over a low heat until softened.Add the bacon back into the pan, alongside with the parsley and thyme and remove from the heat.Whisk the eggs in a different bowl. Stir in the cream, milk, cheese, chilli, nutmeg and paprika.Add the bacon mix to the egg mix and pour everything over the croissants.Mix well, allowing the croissants to soak in the liquid for a few minutes.Pour the mixture into a ovenproof dish and bake for 60 to 75 minutes, depending on if you like it crispier or softer.Cover the dish loosely with foil after 30 minutes of baking to prevent it from over browning.